Improvement in burglar-alarms



EZEKIEL M. HEDRlGKSON, 0F BROOKLYN, NEN/V YURK.

Specification forming part of Letters Patent No. llo'l,

December 26, 187%.

dated June 2, iizlll; application filed To all 'whom it, may concern:

Be it known that l, Estimer. M. HENDRICK- sorr, ot Brooklyn, Kings county, in the State ct' New Yorl ,'have invented certain Improvements relating to Burglar-Alarms, ot which the following is a spccilication z I lily alarm operates without the necessity for magnetic batteries or analogous apparatus, and can induce a loud and repeated al'arm either at the point where the burglarious entrance occurs or at a distant point, asin the sleeping-room of thejanitor ot' the building.

The following is a description ot' what I consider the best means of carrying out thein vention.

A series of hammers actuated by a spring or weight causes the explosion successively ot a number of small tire-arms, by exploding powder successively in each ot a series of barrels provided with peroussioncaps.,

The accompanying drawings form a part of this specification.

Figure l is a side view, and Fig. view, ot` the mechanism. inal section.

Similar lctttu's of reference indicate like parts in 'all the figures.

A is a flooring or inondation oi plank. B isa barrel mounted on suitable bearings and carrying projections b, having each a roller adapted to act successively on levers C, a series ci' which hold up hammers D mounted loosely on the shalt or axis E, and actuated by sprin G through the' medium of links g, so that on bein g liberated from the stop-levers U the several hammers will fall not only ly the torce of gravity, but also by the action of the spring G. In the path ot' each hammer D is the percussioh-cap h, on a suitable nipple on a barrel, E, which may be charged with powder and an appropriate wad, so as by the explosion of the powder to cause a loud report when each hammer falls. The barrel or cylinder B `is provided with a gear-wheel, which meshes into another ou aneighboring shaft, F, which is actuated by a strong volute spring, f, arranged as indicated in lig. i. e. suitable ratchet being provided the spring/i is wound up by means ot' the hand-crank lf", and a sutlicient iorcc being thus provided l'or giving the barrel li a cxjnnplete revoluon, the

2 is a back `Fig. 3 is a longitudapparatus is ready to act so soon as the burglar shall disturb the stop, which under ordinary conditions prevents its action. This stop, which retains the parts in the inert condition under ordinary circumstances, is in the form of a bell-crank lever, I, turning on a fixed center, t, and having a hook or shoulder, I', on one yarm, which engages with the corresponding projection B on the gear-wheel of the barrel B. The partsl/ and B are held engaged or locked together by the force of a gentle spring, J, until a pull is received on the wire K, which may be connected to a door, windowsash, or other part 'which it is desired to guard. f

The several hammers being set so that they are held up by their respective levers U, and the spring j'being wound up, when the door is operated or the window-sash raised it coinmunicates, by means not represented, but which will involve no diliiculty, a pulling'force on the wire K, sufficient to overcome the tension of the spring J and turn the bellcrank lever l su iliciently to separate the parts l' B', under which conditions the spring j' and its connections induce a rotary motion of the barrel I3, with the eftect ot successively dropping the several hammers D and 4exploding the several charges of pow-der.

l insure a moderate and tolerabl y stead y 1no tion ofthe barrel B when in operation, by means ot' an escapement analogous to that ein ployed in clocks and watches. The gear-wheel on the barrel B gears into another ot' smaller diameter, which carries a toothed escapementwheel, M, which acts on the two pallets of what is known in clock-work as a verge, nia-rl;-

ed N in the ligures, and, by giving a rapidly a. corresponding motion to the long'lever 0, 'which carries an adjustable weicht or pendulum, T. By adjusting this latter the time of the oscillations of the verge maybe varied, and consequently the rapidity ot' the rotation ot' the'barrel ll.

l esteem it preferable to arrangetlie parte and rollers li on the drum la, so that the hammers shall fall and the explosions ot' the pow der be induced rather at irregular intervals. An irregular succession ot' explosions is more likely to attract the attention of people in the oscillating motion to the verge, communicates streets, and to arouse all the people in the building.

Some of the details' of the apparatus may be varied within vide limits. Thus, gravity instead of a spring, J, may be employed to hold the` parts I B' in contact, or the apparatus may serve `with success without either. 1t may depend simply on the friction of those parts on each other when properly formed to hold them in contact until a pull is felt on the connection K, which may be a cord instead of4 wire. The projections b may serve without rollers. The hammers may serve by gravity alone, or by a spring'orce alone. The barrel B may be actuatedby a spring applied directly instead of through-gearing, or by the force of a weight applied through acord or Wire rope.

The above construction suppcses the important shoulders I' B to be square, so that there is no tendency to separate or to remain engaged, except by the slight force due to friction. It may be necessary in some situations to provide against a-possibility of a burglar cutting the wire before operating the door or Window. To guard against this I propose to arrange the lever I, or its equivalent stop, so that there shall be a constant tendency to let go of the Wheel and to restrain-this tendency by the wire orether connection K. Un-

der such conditions the operating of the door or Window should slacken the wire instead of pulling it, and the cutting of thewire would have theV same e'ect in liberating the alarm. The wire can-be connected to a slightly-yielding board in the floor, so that it will be operated when that part of the Afloor is stepped on. I esteem all such parts the equivalents of the door or window specified.

I claim as my invention- The escapement M N and adjustable ,pendu-A lum O P or ltheir equivalents, the motive power f or its equivalent, in ccmbinatiouwith theseries of discharging means 11,0, D, and

G,.arranged relatively to a correspondingv .Inl testimony whereof I hate hereunto set .my hand this 24th day of December, 1872, in

the presence of two subscribing witnesses. E. M. HENDRICKSON.

' i Witnesses:

WM. C. DEY, ARNOLD HRMANN. 

